Generally, a LED lighting device is characterized as an electronic device converting electric energy into light energy using LED chips installed on a printed circuit board; therefore, in case a high-powered LED lighting device is needed, there is a problem that inevitable heat from the LED chips should be effectively released.
Accordingly, the temperature of the LED lighting device should be controlled at a suitable level, and if it is not guaranteed, there might be difficulties in efficiency and durability of the LED lighting device.
Moreover, the light emitted from a LED lamp would not be beamed down to a long distance because the unit capacity of the LEDs, which is installed in the lamp, is relatively small and the LEDs emit light only through their surfaces. Especially, a LED lighting device cannot be applied to sports facilities indoor or outdoor, which are known to need large amount of light at a time, due to severe glairiness of LEDs compared to the light source of a general lighting device. In addition, a LED lighting device is well known to have a problem that it cannot provide uniform ratio of illuminance.